1. Tại sao không nên kết hôn cận huyết? Kết hôn cận huyết dẫn đến hậu quả gì? Tại Việt nam, em có biết trường hợp nào kết hôn cận huyết dẫn đến hậu quả như thế nào không?

The phylogenetic tree illustrates the relationship between humans and our closest living relatives. the tree was based on biochemical comparisons, including dna and amino acid sequences. according to the biomolecular data, we could infer that

The cretaceous period spanned the time interval between and 65 million years ago. 250 million 144 million 75 million 200 million

During crossing-over, a. genetic material is exchanged between nonsister chromatids, resulting in new combinations of alleles. b. nonsister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. c. one homologous chromosome of a tetrad is exchanged with another tetrad, resulting in new combinations of alleles. d. sister chromatids from each homologous chromosome of a tetrad are exchanged, resulting in new combinations of alleles. e. genetic material is exchanged between sister chromatids, resulting in new combinations of alleles.